/*
* Copyright 2015, 2016 Tagir Valeev
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package one.util.streamex;
import java.util.Spliterator;
import java.util.function.Consumer;
/**
* @author Tagir Valeev
*/
/* package */class CharSpliterator implements Spliterator<String> {
private final CharSequence source;
private final char delimiter;
private int pos;
private final int fence;
private int nEmpty;
private String next;
private final boolean trimEmpty;
CharSpliterator(CharSequence source, char delimiter, boolean trimEmpty) {
this.source = source;
this.delimiter = delimiter;
this.fence = source.length();
this.trimEmpty = trimEmpty;
}
// Create prefix spliterator and update suffix fields
private CharSpliterator(CharSpliterator suffix, int fence, boolean trimEmpty, int suffixNEmpty, int suffixPos) {
this.source = suffix.source;
this.delimiter = suffix.delimiter;
this.fence = fence;
this.trimEmpty = trimEmpty;
this.pos = suffix.pos;
suffix.pos = suffixPos;
this.nEmpty = suffix.nEmpty;
suffix.nEmpty = suffixNEmpty;
this.next = suffix.next;
suffix.next = null;
}
private int next(int pos) {
if (pos == fence)
return pos;
if (source instanceof String) {
int nextPos = ((String) source).indexOf(delimiter, pos);
return nextPos == -1 ? fence : nextPos;
}
while (pos < fence) {
if (source.charAt(pos) == delimiter)
return pos;
pos++;
}
return fence;
}
@Override
public boolean tryAdvance(Consumer<? super String> action) {
if (nEmpty > 0) {
nEmpty--;
action.accept("");
return true;
}
if (next != null) {
action.accept(next);
next = null;
return true;
}
if (pos > fence) {
return false;
}
int nextPos = next(pos);
if (trimEmpty) {
while (nextPos == pos && nextPos != fence) {
nEmpty++;
nextPos = next(++pos);
}
}
String str = source.subSequence(pos, nextPos).toString();
pos = nextPos + 1;
if (trimEmpty && nextPos == fence && str.isEmpty()) {
nEmpty = 0; // discard empty strings at the end
return false;
}
if (nEmpty > 0) {
next = str;
nEmpty--;
action.accept("");
} else
action.accept(str);
return true;
}
@Override
public Spliterator<String> trySplit() {
int mid = (pos + fence) >>> 1;
int nextPos = next(mid);
if (nextPos == fence)
return null;
if (trimEmpty && nextPos == mid) {
while (nextPos < fence && source.charAt(nextPos) == delimiter)
nextPos++;
return nextPos == fence ?
new CharSpliterator(this, mid, true, 0, nextPos + 1) :
new CharSpliterator(this, mid, false, nextPos - mid - 1, nextPos);
}
return new CharSpliterator(this, nextPos, false, 0, nextPos + 1);
}
@Override
public long estimateSize() {
return pos > fence ? 0 : fence - pos;
}
@Override
public int characteristics() {
return NONNULL | ORDERED;
}
}